Men who are raising alfalfa for use in a regular rotation never leave it over six years; many prefer five, while others make it a rule to plow up their fields every four years; thus the bacteria becomes fixed in the soil of the whole farm. Such farmers use alfalfa as they formerly used clover, to restore fertility needed for profitable crops of grain, hay and forage.
The sod is hard to plow. It is well to do the breaking immediately after the season’s cutting, if possible; disk and harrow it several times and sow to rye for winter pasture, and plant to corn or cotton or potatoes in the spring. The winter’s freezing will help to put it in fine tilth. If it is desired to follow with wheat (not always advisable, however, on account of causing a too rank growth), the sod may be plowed after the year’s second mowing, disked and sowed to rye to prevent the soil from leaching.
Breaking up a well set alfalfa field is no trifling matter. It may be done with three heavy horses, but it is hard work for them, and they will not be able to break more than one acre a day. An authority says the best plan is to use five heavy horses—three in the lead and two on the end of the beam. They can go right along and plow two acres a day. Alfalfa roots are very tough and strong when the plants have attained full growth, and they give a jerky motion to the plow, which is severe on horses’ shoulders. A cast steel plow is the best to use and if it is tempered right a file can just cut it. It can be hammered out thin at the blacksmith’s shop when it becomes too thick to file easily. “The reason for filing, rather than using the hard, thin edge as in other plowing is that the edge needs to be rough as well as thin, or the roots will slip along the sloping edge of the share and not be cut.” It is important that the furrow turned shall not be wider than the plowshare will all the time cut clean, as any main roots that are left uncut will send up a more vigorous growth of stems than before, which, in another cultivated crop will be the same as weeds.
Alfalfa Plant and Roots Showing Bacteria Nodules
Tubercles on Clover Roots
In untreated soil
In inoculated soil